Use krealloc() to re-allocate `din` and `dout`. Don't use devm variant
because the two buffers could be re-allocated multiple times during
runtime. Their life cycles aren't quite aligned to the device's.
Free the memory in cros_ec_unregister() if any.
No need to free memory if krealloc() fails. They will be freed
eventually in either of the following:
- Error handling path in cros_ec_register().
- In cros_ec_unregister().
- Next krealloc() in cros_ec_query_all().
Signed-off-by: Tzung-Bi Shih <[email protected]>
---
Changes from v1:
- Don't use devm.
- Free in cros_ec_unregister().
drivers/platform/chrome/cros_ec.c | 4 +++
drivers/platform/chrome/cros_ec_proto.c | 29 +++++++-------------
drivers/platform/chrome/cros_ec_proto_test.c | 3 +-
3 files changed, 15 insertions(+), 21 deletions(-)
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index 29d3b544dafb..fb8cb8a73295 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -285,6 +285,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
exit:
platform_device_unregister(ec_dev->ec);
platform_device_unregister(ec_dev->pd);
+ kfree(ec_dev->din);
+ kfree(ec_dev->dout);
return err;
}
EXPORT_SYMBOL(cros_ec_register);
@@ -302,6 +304,8 @@ void cros_ec_unregister(struct cros_ec_device *ec_dev)
if (ec_dev->pd)
platform_device_unregister(ec_dev->pd);
platform_device_unregister(ec_dev->ec);
+ kfree(ec_dev->din);
+ kfree(ec_dev->dout);
}
EXPORT_SYMBOL(cros_ec_unregister);
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 473654f50bca..de6bc457e496 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -469,9 +469,9 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
*/
int cros_ec_query_all(struct cros_ec_device *ec_dev)
{
- struct device *dev = ec_dev->dev;
u32 ver_mask = 0;
int ret;
+ u8 *din, *dout;
/* First try sending with proto v3. */
if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
@@ -492,21 +492,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
}
}
- devm_kfree(dev, ec_dev->din);
- devm_kfree(dev, ec_dev->dout);
-
- ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
- if (!ec_dev->din) {
- ret = -ENOMEM;
- goto exit;
- }
+ din = krealloc(ec_dev->din, ec_dev->din_size, GFP_KERNEL);
+ if (!din)
+ return -ENOMEM;
+ ec_dev->din = din;
- ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
- if (!ec_dev->dout) {
- devm_kfree(dev, ec_dev->din);
- ret = -ENOMEM;
- goto exit;
- }
+ dout = krealloc(ec_dev->dout, ec_dev->dout_size, GFP_KERNEL);
+ if (!dout)
+ return -ENOMEM;
+ ec_dev->dout = dout;
/* Probe if MKBP event is supported */
ret = cros_ec_get_host_command_version_mask(ec_dev,
@@ -555,10 +549,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
"failed to retrieve wake mask: %d\n", ret);
}
- ret = 0;
-
-exit:
- return ret;
+ return 0;
}
EXPORT_SYMBOL(cros_ec_query_all);
diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
index 730248be42a7..27b81a5a9880 100644
--- a/drivers/platform/chrome/cros_ec_proto_test.c
+++ b/drivers/platform/chrome/cros_ec_proto_test.c
@@ -180,8 +180,7 @@ static void cros_ec_proto_test_query_all_pretest(struct kunit *test)
/*
* cros_ec_query_all() will free din and dout and allocate them again to fit the usage by
- * calling devm_kfree() and devm_kzalloc(). Set them to NULL as they aren't managed by
- * ec_dev->dev.
+ * calling krealloc(). Set them to NULL as they aren't allocated by kalloc().
*/
ec_dev->din = NULL;
ec_dev->dout = NULL;
--
2.36.1.255.ge46751e96f-goog
On Tue, Jun 07, 2022 at 12:06:23PM -0700, Guenter Roeck wrote:
> On Tue, Jun 7, 2022 at 7:57 AM Tzung-Bi Shih <[email protected]> wrote:
> >
> > Use krealloc() to re-allocate `din` and `dout`. Don't use devm variant
> > because the two buffers could be re-allocated multiple times during
> > runtime. Their life cycles aren't quite aligned to the device's.
>
> While this saves a few lines of code, it is runtime-expensive:
> krealloc() copies the old data, which is a waste of time/resources.
> Maybe it would be better to just use kfree() followed by kzalloc().
Ack. I wasn't aware of the memcpy(). Let's don't use it.
> > @@ -469,9 +469,9 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
> > */
> > int cros_ec_query_all(struct cros_ec_device *ec_dev)
> > {
> > - struct device *dev = ec_dev->dev;
> > u32 ver_mask = 0;
> > int ret;
> > + u8 *din, *dout;
> >
> > /* First try sending with proto v3. */
> > if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
> > @@ -492,21 +492,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> > }
> > }
> >
> > - devm_kfree(dev, ec_dev->din);
> > - devm_kfree(dev, ec_dev->dout);
> > -
> > - ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
> > - if (!ec_dev->din) {
> > - ret = -ENOMEM;
> > - goto exit;
> > - }
> > + din = krealloc(ec_dev->din, ec_dev->din_size, GFP_KERNEL);
> > + if (!din)
> > + return -ENOMEM;
>
> I would suggest assigning the values directly; the new variables don't
> really add value.
checkpatch.pl generated a warning for it. See [1].
Will remove the krealloc()s anyway.
[1]: https://github.com/torvalds/linux/commit/972fdea2e6ece7578915d386a5447bc78d3fb8b8
On Tue, Jun 7, 2022 at 7:57 AM Tzung-Bi Shih <[email protected]> wrote:
>
> Use krealloc() to re-allocate `din` and `dout`. Don't use devm variant
> because the two buffers could be re-allocated multiple times during
> runtime. Their life cycles aren't quite aligned to the device's.
While this saves a few lines of code, it is runtime-expensive:
krealloc() copies the old data, which is a waste of time/resources.
Maybe it would be better to just use kfree() followed by kzalloc().
>
> Free the memory in cros_ec_unregister() if any.
>
> No need to free memory if krealloc() fails. They will be freed
> eventually in either of the following:
> - Error handling path in cros_ec_register().
> - In cros_ec_unregister().
> - Next krealloc() in cros_ec_query_all().
>
> Signed-off-by: Tzung-Bi Shih <[email protected]>
> ---
> Changes from v1:
> - Don't use devm.
> - Free in cros_ec_unregister().
>
> drivers/platform/chrome/cros_ec.c | 4 +++
> drivers/platform/chrome/cros_ec_proto.c | 29 +++++++-------------
> drivers/platform/chrome/cros_ec_proto_test.c | 3 +-
> 3 files changed, 15 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
> index 29d3b544dafb..fb8cb8a73295 100644
> --- a/drivers/platform/chrome/cros_ec.c
> +++ b/drivers/platform/chrome/cros_ec.c
> @@ -285,6 +285,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> exit:
> platform_device_unregister(ec_dev->ec);
> platform_device_unregister(ec_dev->pd);
> + kfree(ec_dev->din);
> + kfree(ec_dev->dout);
> return err;
> }
> EXPORT_SYMBOL(cros_ec_register);
> @@ -302,6 +304,8 @@ void cros_ec_unregister(struct cros_ec_device *ec_dev)
> if (ec_dev->pd)
> platform_device_unregister(ec_dev->pd);
> platform_device_unregister(ec_dev->ec);
> + kfree(ec_dev->din);
> + kfree(ec_dev->dout);
> }
> EXPORT_SYMBOL(cros_ec_unregister);
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 473654f50bca..de6bc457e496 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -469,9 +469,9 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
> */
> int cros_ec_query_all(struct cros_ec_device *ec_dev)
> {
> - struct device *dev = ec_dev->dev;
> u32 ver_mask = 0;
> int ret;
> + u8 *din, *dout;
>
> /* First try sending with proto v3. */
> if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
> @@ -492,21 +492,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> }
> }
>
> - devm_kfree(dev, ec_dev->din);
> - devm_kfree(dev, ec_dev->dout);
> -
> - ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
> - if (!ec_dev->din) {
> - ret = -ENOMEM;
> - goto exit;
> - }
> + din = krealloc(ec_dev->din, ec_dev->din_size, GFP_KERNEL);
> + if (!din)
> + return -ENOMEM;
I would suggest assigning the values directly; the new variables don't
really add value.
Thanks,
Guenter
> + ec_dev->din = din;
>
> - ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
> - if (!ec_dev->dout) {
> - devm_kfree(dev, ec_dev->din);
> - ret = -ENOMEM;
> - goto exit;
> - }
> + dout = krealloc(ec_dev->dout, ec_dev->dout_size, GFP_KERNEL);
> + if (!dout)
> + return -ENOMEM;
> + ec_dev->dout = dout;
>
> /* Probe if MKBP event is supported */
> ret = cros_ec_get_host_command_version_mask(ec_dev,
> @@ -555,10 +549,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> "failed to retrieve wake mask: %d\n", ret);
> }
>
> - ret = 0;
> -
> -exit:
> - return ret;
> + return 0;
> }
> EXPORT_SYMBOL(cros_ec_query_all);
>
> diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
> index 730248be42a7..27b81a5a9880 100644
> --- a/drivers/platform/chrome/cros_ec_proto_test.c
> +++ b/drivers/platform/chrome/cros_ec_proto_test.c
> @@ -180,8 +180,7 @@ static void cros_ec_proto_test_query_all_pretest(struct kunit *test)
>
> /*
> * cros_ec_query_all() will free din and dout and allocate them again to fit the usage by
> - * calling devm_kfree() and devm_kzalloc(). Set them to NULL as they aren't managed by
> - * ec_dev->dev.
> + * calling krealloc(). Set them to NULL as they aren't allocated by kalloc().
> */
> ec_dev->din = NULL;
> ec_dev->dout = NULL;
> --
> 2.36.1.255.ge46751e96f-goog
>